Lay-in type suspended ceiling and panel therefor



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LAY-IN TYPE SUSPENDED CEILING AND PANEL THEREFOR Filed Sept. 30, 1968INVENTOR. DA V/D W AKERSON HIS ATTORNEY United States Patent Office3,504,463 Patented Apr. 7, 1970 U.S. Cl. 52-145 9 Claims ABSTRACT OF THEDISCLOSURE In a lay-in type suspended ceiling, the acoustical panels arecomprised of boards of mineral fiber bonded together with an hydrophilicbinder, which boards are faced with a metal foil facing. Said foilfacing being embossed.

This application is a continuation-in-part of my copending applicationSer. No. 687,583 filed in the United States Patent Ofiice on Dec. 4,1967.

This invention relates to a lay-in ceiling as distinguished from a tileceiling.

One object of this invention is to provide an improvement in the lay-inpanels faced with a metal foil as disclosed in my earlier application.

Another object ofthis invention is to provide a washable, and repeatedlywashable, facing on lay-in panels, which facing also provides a damageresistant surface.

Still another object of this invention is to overcome the warping of thefoil faced panels of my earlier invention when they are exposed toextremely severe variations in humidity.

These and other objects will be understood by those skilled in the artfrom the accompanying specification and drawings in which:

FIG. 1 is a prospective view from beneath of a lay-in ceiling, and

FIG. 2 is an enlarged view of a portion of one of the panels from FIG.1.

Of the many types of ceilings currently being installed,

Commonly, lay-in ceilings incorporate panels or boards of a dimension ofat least 2' x 2. In contrast, tile ceilings utilize tiles of generally1' x 1', although sometimes such tiles are provided in 1' x 2' sizes.

Another distinguishing feature between the lay-in systems and tileceilings is that the large panels of the lay-in ceilings are supportedby resting upon a grid made up of runners and cross members which are ofan inverted T shape in cross section. Thus the lay-in panels merely reston the suspension system, which is generally referred to as an exposedsystem. In contrast, tiles are mounted in a number of ways Which do notnormally expose the suspension system. Tiles may be nailed, screwed, oradhered to a completed ceiling, or they may be mounted in a suspensionsystem specifically designed to hide the suspension system in kerfs cutinto edges of the tiles.

Lay-in panels are merely square cut on their edges and extend in size,as indicated above, from 2' x 2 in dimension on up, with 2' x 4' beingthe most common dimen sion. Larger sizes are sometimes provided, butnormally not in excess of 2' in Width. Thus, panels 2 x 5' and 2 x 6'are known.

The lay-in system generally enjoys a greater volume of sales in theindustry, due largely to the lesser cost per square foot of producing asquare cut board as opposed to one requiring additional working of theedges, such as is required with tiles. Another reason for the generaleconomy of lay-in systems is the ease of installation and the minimumamount of suspension system needed.

For certain applications, however, lay-in panels were not acceptableprior to the invention disclosed in my earlier application. Generally,in areas of excessive humidity, such as restaurant kitchens, bathrooms,and swimming pool areas, a highly washable surface is required. Forthese types of applications, recourse has been had to tile systems inwhich the tiles are faced with a metal foil, generally extending atleast part way up the edges of the tiles. Such metal foils serve toprovide a hard and washable surface for such applications as mentionedabove where repeated washing or sanitizing, such as in hospitals, isrequired.

As pointed out in my earlier application, previous to my inventiondisclosed therein, lay-in panels had not been provided with metal foilfacings. It is not known exactly why such products had not beenavailable; how ever, it is believed due to the fact that large panelstend to sag or pillow in the center, thus giving an undulating andunpleasing appearance to the ceiling.

Because of fire code requirements, most all lay-in panels are made frommineral fibers bound together with a suitable binder. The common binderis starch, which is hy-drophilic. Starch, of course, is used primarilyfor economy. When such panels are mounted in high humidity areas, beingsupported only at their edges, the humidity tends to weaken the starchbond, thus permitting the board or panel to sag noticeably toward thecenter. Any additional Weight added to the panel tends to aggravate thisdifficulty.

Even without added Weight, such mineral fiber panels bound withhydrophilic binders have required additional treatment such as a resincoating on the back side in order to bring the sag characteristicswithin acceptable limits. Until my invention disclosed in my earlierapplication, it was not to be expected that the added weight of metalfoil facings could be tolerated, since metal foils are not in themselvesself-supporting.

As disclosed in my earlier application, I discovered that foil facedmineral fiber boards with an hydrophilic binder could be produced whichdo not sag beyond acceptable limits. I have found, however, that panelsso produced tend to warp in a different manner if exposed to extremehigh humidity and then are subjected to more normal humidity, all asmore fully described hereinafter.

In the drawings, FIG. 1 shows a suspension system for a lay-in system,including lay-in panels 10, longitudinal runners 12, and cross members14.

The cross section of a runner 12 is shown in FIG. 1 as comprising avertical web 16 and horizontally disposed flanges 18 and 20. The crosssection of the cross members 14 is not shown but is substantiallyidentical to the cross section of the runners 12.

The runners 12 are supported from a permanent superstructure, such as aconcrete deck (not shown), by means of wires 22 fastened to such a deckat one end and at the other end to the web 16 of the runners 12.

It will be seen that the panels 10 merely rest upon the horizontalflanges 18 and 20 of the suspension system runners 12 and cross members14. As such, the suspension system comprised of the runners 12 and thecross members 14 is exposed, at least to the extent of showing one faceof the flanges 18 and 20. This arrangement permits the panels 10 to beremoved by pushing upwardly, thus permitting access to pipes, duct Work,electrical conduits, and the like hidden above the suspension systemceiling and beneath the deck above. The ease of access is another of thereasons for the general popularity of this type of ceiling.

The panels of the instant invention are also shown in FIG. 2, whereinthey are shown to comprise a body portion 24 and a metal foil facingmember 26.

The body portion 24 is comprised of felted synthetic mineral fibersbound together by a suitable economic binder such as the hydrophilicbinder starch. The facing 26 is preferably of aluminum foil but may beany of a number of other metal foils, such as tin, brass, stainlesssteel, and the like.

The metal foil facing 26 is preferably adhered throughout substantiallyits entire extent by means of an adhesive to the front surface of thebody 24.

The panel 10 is also provided with relatively minute acoustical openings28 punched through the metal foil 26 and into the body board 24. Theseacoustical openings are generally of a size between and in diameter.There are a myriad of such minute perforations in the front surface ofthe panel 10. These acoustical openings provide access into the soundabsorptive body board 24 for acoustical energy-sound-impinging upon theface of the metal foil 26. The metal foil itself is, of course, notacoustically absorptive and the body board 24, in the absence of theopenings 28, would not be particularly sound absorptive either. Theopenings 28 permit the sound to enter well into the body board 24, wherethe sound is absorbed in known fashion in the interstices of the fibers.Generally the fibers arrange themselves in layers parallel to the planeof the panel 10 and, consequently, some means of introducing the soundenergy into the body of the board is required. However, these openings28 also permit access into the interior of the board for the humidity ofthe atmosphere which deleteriously affects the hydrophilic binder.

In one accepted test for sagging, a ceiling of lay-in panels issupported in an enclosed tent, or room, where the humidity andtemperature may be controlled. In such a test, the maximum permissiblelimit along the 4 length of a panel is 0.25" downward sagging. Asdisclosed in my earlier application, applicant has found, contrary toexpectations, that with a metal foil facing such large panels will sagonly between .08" and .10".

I have found, however, that when the panels of my earlier invention areexposed to exteremely high humidity and then are subsequently exposed tolesser or more normal humidity, while they do not sag excessively, theydo warp in an unusual manner. Under such circum stances the boardsurface is not really very much below the level of the suspension systemand falls well within the usually considered acceptable limit of 0.25"downward sagging mentioned above; however, the four corners of the boardraise up from A" to /2" above the horizontal flanges of the suspensionsystem. This creates a warped effect at the corners which isaesthetically disadvantageous. I have found that an embossed foil,preferably an embossed aluminum foil, of not in excess of .0025" inthickness overcomes this warping problem completely. Indeed, I havefound that such a foil is so effective that it not only prevents theabove-mentioned corner warping but also eliminates sag to such an extentthat the normal resin coating on the back side of the board may beeliminated.

In the drawings the metal foil is shown as embossed as indicated at 30;however, it must be understood that the drawings are merely an attemptto show the embossing which is preferably of the type referred to as astucco pattern by the foil supplier. Actually, various patterns ofembossing will serve although an embossing extending substantially overthe entire surface of the foil applied to the front surface of the board24 is preferred.

I have also discovered that a foil of .0025" or less works well toeliminate such warping of the corners, and incidentally to improve thesag characteristics, whereas an aluminum foil that is embossed and whichis .004" thick does not quite give the proper effect.

The examples of Table I were all prepared with a W base board of mineralfibers bound with starch and having the foil facings indicated above.The examples were all tested in the high humidity tent referred to aboveand the sag and corner warp values listed in Table I were thus obtained.It will be seen only those examples with embossed foils performedsatisfactorily on both sag and corner warp while all examples weresatisfactory with respect to sag. The most satisfactory corner warpexamples were Examples III and IV having embossed foils of less than.004" thickness.

'It is not known, nor need it be known why embossed foils perform togive these results; however, it is theorized that there is an accordioneffect in the foil such that it will expand and contract with the board,thus eliminating the application of additional stresses to the boardsurface when it is subjected to the extremes of humidity referred toabove.

As indicated above, and as illustrated in the examples, it has beenfound that a resin coating, as often applied to the back side of theboard, is not required when such thin embossed foils are used.

While reference has been made herein to dimensions of 2' x 2', 2' x 4,and larger for the panels 10, it is to be understood that in theindustry these dimensions refer to what is called nominal dimensions andthat actually such panels will be a few fractions of an inch smallerthan the indicated sizes in order to accommodate the thickness of theweb 16 and to permit insertion and removal of the panel 10. For example,the nominal 2' x 4' size, which is most common, is in actuality 111% x311%".

By the term foil as used herein, applicant refers to metal foils whichare of such a thickness as to be not selfsupporting in the dimensionsreferred to above, such as the nominal 2' x 2 size or larger.

I claim:

1. An acoustical panel comprising a board of mineral fibers boundtogether by an hydrophilic binder, said board having a substantiallysmooth planar face and being of at least substantially 2 x 2 indimension in the major plane thereof, a metal foil facing adhered tosaid face of said board throughout substantially the full extent of saidface, and said foil being embossed throughout substantially the fullextent thereof with a pattern.

2. The panel of claim 1 in which said foil is less than about .004 inthickness.

3'. The panel of claim 1 in which acoustical Openings extend throughsaid foil and into said board to provide access to the interior of saidboard for sound energy impinging upon the exposed face of said foil.

4. The panel of claim 3 in which said foil is less than about .004" inthickness.

5. The panel of claim 3 in which said board is free of any resin coatingon the opposite face of said panel.

6. The panel of claim 3 in which the side edges of said board aresubstantially free of foil.

7. A suspended acoustical ceiling of the lay-in type comprising asuspension grid having a plurality of parallel runners and a pluralityof cross members extending be tween runners, said runners and crossmembers being an inverted T shape in cross section, a plurality ofacoustical panels supported horizontally by said grid with the edges ofsaid panels resting on the horizontal flanges of said runners and crossmembers, each of said panels being comprised of mineral fibers boundtogether by an hydrophilic binder to form a board, the dimensions ofeach of said boards being at least substantially 2' x 2' in the plane ofthe ceiling, each of said boards having a substantially smooth planarface, a metal foil facing adhered to said face of said board throughoutsubstantially the full extent of said face, said panels being mounted insaid suspension grid with their foil facing downwardly to- Ward theinterior of the room, and said foil being embossed throughoutsubstantially the full extent thereof with a pattern.

8. The panel of claim 7 in which acoustical openings extend through saidfoil and into said board to provide access to the interior of said boardfor sound energy 1 References Cited UNITED STATES PATENTS FOREIGNPATENTS 12/1965 Great Britain.

5 ALFRED C. PERHAM, Primary Examiner US. Cl. X.R.

